A conventionally known power transmission chain for use in a chain-type continuously variable transmission for automotive vehicles includes: a plurality of link plates each formed with two pin holes apart from each other by a predetermined pitch; and a plurality of pin members for bendably interconnecting these link plates. As disclosed in Japanese Unexamined Patent Publication No. H8-312725, for example, such a power transmission chain is formed by placing the link plates in layers in thickness-wise and longitudinal directions of the chain and press-inserting the pin members through the pin holes for interconnecting the link plates into an endless loop form.
In the above power transmission chain, the link plates are placed in layers in a manner that the pin holes thereof are mutually aligned, while the pin members each including two pins are press-inserted through the pin holes in a manner to penetrate the chain in the width-wise direction thereof. The chain having such a structure can hardly be bent in any direction except for a direction about an axis of the pin member and is extremely low in free play such as backlash. Hence, the fabrication of the above power transmission chain requires the pin members to be exactly positioned by maintaining the longitudinal position thereof substantially vertically to side surfaces of the link plates and maintaining a predetermined pitch between a respective pair of adjoining pin members, before the pin members are press-inserted through the link plates. If this procedure is not practiced, the pin member may be out of alignment with the pin holes or seizure between the pin member and the pin hole may occur. Consequently, the pin members cannot be press-inserted through the pin holes.
In order to press-insert the pin members through the link plates, these components must be maintained in a positional relation that they are positioned just as they are assembled in the chain. This positioning of the components makes a chain assembling operation cumbersome.
In view of the foregoing problem, it is an object of the invention to provide a manufacture method of power transmission chain which facilitates the fabrication of the chain by providing the exact positioning of the pin members or the link plates, and to provide a power-transmission-chain manufacturing apparatus employed by the method.